I purchased my printer 18 months ago and it has worked well. However a few days ago the black ink refused to print. I have changed the cartridge, cleaned the printhead, unplugged and replugged in the printer, all to no avail. Checking on the internet it appears that many people have had the same problem and always with the black ink not printing.
To get the printer repaired is going to cost money and HP's help is as usual absolutely useless. A new printer is £97 from John Lewis (having reduced from £129 that I paid 18 months ago!)
Anyone any ideas at all at how to get the black working again?
Oddly enough I have used an HP B209 printer for just over 18 months and have had exactly the same problem with the black cartridge only. I looked at the link that Northumbria61 gave and found that I had done everything suggested there, even to replacing the print head on the printer. I finally gave up and purchased the HP6520 that I have had for just over a week. I will keep my fingers crossed on this. All very coincidental don't you think? - specifically the black cartridge?
compumac - the 6520 is virtually identical with the 6510. In fact because I had a lot of cartridges already for the 6510, I bought the 6520. However it may not last any longer than my 6510. Loking on the internet you will see that lots of owners have the same problem - almost as if HP design in a failure to encourage sales! Hopefully this will backfire on them. Ther must be an inherent design fult.
I believe your printer uses 4 x 364 cartridges which fit into the printer head.
Have you tried removing the Printer head and cleaning it?
Usually when the printer cleans the printer head ink is deposited in a small tray usually to the right of the printer just below where the cartridges park. After a while you get a build up of thick ink preventing the printer head from being cleaned properly.
To remove the printer head: remove cartridges, pull leaver upwards this is to the right of where the cartridges fit, you should now be able to remove the printer head to check and clean it manually.
In respect of my issue with the B209 which had 364 cartridges I had removed the print head, cleaned it and also replaced with a brand new one.
I think that in you referring to the lever and the print head they do not exist on the 6520/6510 but did on the B209 types.
On some previous Photosmart units there was a lever immediately to the right of the cartridges and if you removed the cartridges you were able to pull the lever up, it then disengaged the printhead for you to clean
I fixed all of my HP problems in one fell swoop - by buying an Epson from Tesco for a little more than £40. I'd always had Epson printers, but my wife - who isn't authorised to buy any technology for the home - got me the HP for my birthday. I put up with the damn thing for a year.